Patent GB-193049-A (GB)
Abstract: 193,049. Janson, G. H. Feb. 9, 1922, [Convention date]. Automatic and semi-automatic exchange systems.-In systems in which the selection of an idle line in a desired numerical group is effected by temporarily-used numerical selectors, such as group selectors, number registers or keyboards, and non-numerical selectors, such as line searchers, each numerical group of outgoing lines NG1, NG2, NG3, Fig. 1, is provided with one or more non- numerical selectors LS1, LS2, LS3, which are accessible to all the numerical selectors GV1, GV2, GV3. General arrangement. Each numerical group NG1, Fig. 2, say, may be divided into a number of sub-groups UG1, UG2, UG3, each sub-group having allotted to it a line searcher LS1, LS2, LS3 accessible to all the numerical selectors GV1, GV2, GV3. Each numerical selector has devices GS1, GS2, GS3, termed gronp searchers, one for each numerical group of outgoing lines, for selecting an idle, line searcher in the selected group. The group searchers may select the line searchers in a different order of sequence. The incoming line is marked only in that or those connecting apparatus, such as AK, Fig. 1, associated with the outgoing lines of the subgroup selected by the group selector and the group searcher. Circuit connections. Figs. 5. 6, 7 show two sub-groups IG1, IG3, Fig. 5, of incoming lines, with associated group selectors GV1, GV3, and three sub-groups UG1, UG2, UG3, Fig. 7, of one numerical group of outgoing lines. Each outgoing sub-group has a relay line searcher LS1, LS2, LS3, an idle line searcher being selected by a group searcher GS1, GS2, or GS3. Each outgoing line UL1, say, is multipled to all the contacts of a cross-bar selector AK1, Fig. 6, represented by contacts KG11, KG12, &c., and vertical and horizontal magnets AR1, AR2, AR3 and MR1, MR2, MR3. The marking wires MS for identifying the incoming line are extended by one of the relays MKR1, MKR2, MKR3 to the wires MS1 individual to the sub-group containing the selected outgoing line, and then by one of the relays GR1, GR2, GR3 to the cross-bar selector individual to the outgoing junction. Connection of calling line 1L1 to group selector GV1. When a subscriber removes his receiver, his line relay ASR1 energizes over circuit 1, locks up so as to be independent of relay KR, and energizes a relay FR, which in turn energizes relay KR. The holding circuit of each line relay ASR2 &c. is dependent on the preceding relay, so that only one line relay in the sub-group can be energized at a time. Relay FR energizes over circuit 3 relay HR1 of the group selector GV1, thereby connecting its relays OR1, OR2 to the a and b wires of the calling line. Operation of group selector. The subscriber transmits two successive impulse combinations, each consisting of an impulse over one or other or both leads. The first impulse energizes one or both of the relays OR1, OR2, thereby energizing relay HR3 and one or both of the relays OR3, OR4, which lock up dependent on relav FR and short-circuit relay HR1. When the impulse or impulses cease, the relay HR3 energizes over circuit 7, and removes the short circuit around relay HR1. The second impulse energizes one or both of the relays OR1, OR2, which now lock up dependent on relay HR3. A circuit 8 is thus closed by one or both of the relays OR1, OR2, and one or both of the relays OR3, OR4 for the selected numerical group relay GV1R1, say. Selection of idle outgoing line. If the first line searcher LS1 is disengaged, a circuit 9 is closed through relays PAR1, GSR1, which energize and bring into circuit the relays DR, CR, which mark the line searcher LS1 and the group searcher GS1 as busy. Relay DR closes a circuit 11 through the relay LSR1, say, of the first idle outgoing circuit accessible to the searcher LS1. Relay LSR1 locks up in series with relay ER to disconnect the other relays in the searcher. Operation of connecting apparatus. The relay GSR1 of the group searcher energizes over circuit 10 a relay MKR1 which extends the marking wires MS to the wires MS1 associated with the connecting apparatus AK1, AE2, AK3 of the lines of the sub-group VG1. The relay LSR1 also energizes over circuit 12 a relay GR1 which extends the wires MS1 to the operating magnets MR1 &c., AR1 &c. of the cross-bar selector AK1 individual to the selected outgoing line UL1. The magnet MR1, say, corresponding to the subgroup containing the calling line, energizes over a circuit 13, and completes a circuit 14 for a magnet AR1, say, this circuit extending over the armatures of relays MKR1, GV1R1, ASR1 to earth. The contacts EG11 are thus closed to connect the incoming line to the junction UL1. A holding circuit 15 is closed through the relay ASR, Fig. 7, of the outgoing junction, the holding winding HL of relay AR1, and the cut-off relay UR1 of the incoming line. The relay ASR1 is thus de-energized, freeing the group selector GV1 for common use, and opening circuits 2 - - 14. Modified arrangement using less group searchers GS and switching relays MKR. As the group searchers are used for a shorter time than the group selectors, a smaller number may be used than in the system just described. This is effected by dividing the incoming lines into a number of groups equal to the number of group searchers in e a c h numerical group, each group of incoming lines having a relay device BS2, shown in the upper part of Fig. 6, for connecting in sequence the lines which call simultaneously in this group. If the numerical group relay GV3R1, Fig. 6, is energized as the result of a call in group IG3, Fig. 5, a circuit 16 is closed for relav BSR1, which locks up in series with a relay BR, which opens the energizing circuits of other relays such as BSR2. The marking wires MS3 of the calling group only are thus connected to the armatures of the marking relays such as MKR1. Preventing selection of line searcher LS1, say, when all the outgoing lines of group UG1 are engaged. This is effected by energizing the relay ER to mark the searcher busy. Specification 13524/14 is referred to. The Specification as open to inspection under Sect. 91 (3) (a) states that the connecting apparatus AK may consist of a number of callfinders, which simultaneously hunt for the incoming trunk, the group searchers GS starting all idle call-finders of a sub-group of outgoing lines. This subject-matter does not appear in the Specification as accepted.